1. Field of the Invention
This invention relates to a panel door with an articulated break-away cam design which engages guide tracks. Upon impact, articulating break-away devices pivot on an axis and allow the door to slide free of the fixed guide track with little or no damage to the door. The design of the break-away devices allows for simple resetting of the door.
2. Description of the Prior Art
Many industrial locations, such as warehouses and factories, have high traffic of vehicles, such as forklifts. Such locations frequently have accidents where the vehicles strike a large industrial door. In order not to disrupt the operation of the industrial location, it is important to be able to avoid or minimize any damage, if possible, and further to reset any impacted door quickly.
These concerns have been addressed by the use of flexible curtains in place of doors, these flexible curtains pulling out of the guide tracks upon impact with minimized damage. Such doors are disclosed in U.S. Pat. No. 4,478,268 to Palmer entitled "Door Structure". A variation of this concept is shown in U.S. Pat. No. 4,601,320 to Taylor entitled "Industrial Door".
However, there are still many industrial locations where a flexible curtain door is not desired, such as exterior doors which lead to the outside where a solid door is desirable for security purposes, particularly when the door is fully closed. U.S. Pat. No. 5,535,805 to Kellogg et al. entitled "Overhead Door" uses a linear reciprocating plunger which engages a guide track with one or both sides of the track including an angled disengagement portion. However, this structure requires a complicated plunger arrangement which, along with the guide track, is expensive to manufacture and difficult to maintain.